Disable asserts in histogram code except in --testing-mode

The assertions in histogram.c are algebraically correct,
but due to floating point errors may not actually be true.
This change disables them except when in testing mode.
The tests in charts.at rely upon them being enabled.
Closes bug #36395

diff --git a/src/libpspp/assertion.h b/src/libpspp/assertion.h
index 5b10d638abb2f7bf6cfcb7a87a3d77ca305b99c2..237710813d52ffaa1237f17e55ddbf981e0429e8 100644 (file)
--- a/src/libpspp/assertion.h
+++ b/src/libpspp/assertion.h
@@ -36,3 +36,6 @@
 #else
 #define expensive_assert(EXPR) ((void) 0)
 #endif
+
+
+#define testing_assert(EXPR) do {if (settings_get_testing_mode ()) assert (EXPR); }  while (0);

diff --git a/src/math/histogram.c b/src/math/histogram.c
index afc40013e02865f46f82549599f4f9cb84812706..51916a3d8baef7649f1920d6c2635c90a36824a1 100644 (file)
--- a/src/math/histogram.c
+++ b/src/math/histogram.c
@@ -84,6 +84,10 @@ double get_slack (double limit, double half_bin_width, int *n_half_bins)
    ADJ_MIN and ADJ_MAX are locations of the adjusted values of MIN and MAX (the range will
    always be  equal or slightly larger).
    Returns the number of bins.
+
+   The "testing_assert" expressions in this function should be algebraically correct.
+   However, due to floating point rounding they could fail, especially when small numbers
+   are involved.  In normal use, therefore, testing_assert does nothing.
  */
 static int
 adjust_bin_ranges (double bin_width, double min, double max, double *adj_min, double *adj_max)
@@ -97,7 +101,7 @@ adjust_bin_ranges (double bin_width, double min, double max, double *adj_min, do
   double lower_slack =  get_slack (min, half_bin_width, &lower_limit);
   double upper_slack = -get_slack (max, half_bin_width, &upper_limit);
 
-  assert (max > min);
+  testing_assert (max > min);
 
   /* If min is negative, then lower_slack may be less than zero.
      In this case, the lower bound must be extended in the negative direction
@@ -108,7 +112,7 @@ adjust_bin_ranges (double bin_width, double min, double max, double *adj_min, do
       lower_limit--;
       lower_slack += half_bin_width;
     }
-  assert (lower_limit * half_bin_width <= min);
+  testing_assert (lower_limit * half_bin_width <= min);
 
   /* However, the upper bound must be extended regardless, because histogram bins
      span the range [lower, upper). In other words, the upper bound must be
@@ -116,7 +120,7 @@ adjust_bin_ranges (double bin_width, double min, double max, double *adj_min, do
   */
   upper_limit++;;
   upper_slack += half_bin_width;
-  assert (upper_limit * half_bin_width > max);
+  testing_assert (upper_limit * half_bin_width > max);
 
   /* The range must be an EVEN number of half bin_widths */
   if ( (upper_limit - lower_limit) % 2)
@@ -159,7 +163,7 @@ adjust_bin_ranges (double bin_width, double min, double max, double *adj_min, do
 
       if (upper_slack > lower_slack)
         {
-          assert (upper_slack > half_bin_width);
+          testing_assert (upper_slack > half_bin_width);
 
           /* Adjust the range to the left */
           lower_limit --;
@@ -169,7 +173,7 @@ adjust_bin_ranges (double bin_width, double min, double max, double *adj_min, do
         }
       else
         {
-          assert (lower_slack >= half_bin_width);
+          testing_assert (lower_slack >= half_bin_width);
 
           /* Adjust the range to the right */
           lower_limit ++;
@@ -197,8 +201,8 @@ adjust_bin_ranges (double bin_width, double min, double max, double *adj_min, do
   *adj_min = lower_limit * half_bin_width;
   *adj_max = upper_limit * half_bin_width;
 
-  assert (*adj_max > max);
-  assert (*adj_min <= min);
+  testing_assert (*adj_max > max);
+  testing_assert (*adj_min <= min);
 
   return (upper_limit - lower_limit) / 2.0;
 }

diff --git a/tests/output/charts.at b/tests/output/charts.at
index 302e05b1512c912d93e3081980f9b1dcfdc59727..049fc281922acecfb022fcedaf2eaeda53badc00 100644 (file)
--- a/tests/output/charts.at
+++ b/tests/output/charts.at
@@ -151,6 +151,7 @@ frequencies pos neg pn
 ])
 
 
-AT_CHECK([pspp -O format=csv histogram.sps], [0], [ignore])
+dnl The --testing-mode flag is important!!
+AT_CHECK([pspp --testing-mode -O format=csv histogram.sps], [0], [ignore])
 
 AT_CLEANUP